1. Field of the Invention
The present invention relates to a surface discharge type full color surface discharge type plasma display panel and a process for manufacturing the same. More specifically, the present invention relates to a full color ac plasma display device high in resolution and brightness of display such that it is adaptable to a high quality display, such as a high definition TV, and can be used in daylight.
2. Description of the Related Art
A plasma display-panel (PDP) has been considered the most suitable flat display device for a large size, exceeding over 20 inches, because a high speed display is possible and a large size panel can easily be made. It is also considered to be adaptable to a high definition TV. Accordingly, an improvement in full color display capability in plasma display panels is desired.
In the past, two electrode type dc and ac plasma display panels have been proposed and developed. Also, a surface discharge type ac plasma display panel, among other plasma display panels, has been known to be suitable for a full color display.
For example, a surface discharge type ac plasma display panel having a three electrode structure comprises a plurality of parallel display electrode pairs formed on a substrate and a plurality of address electrodes perpendicular to the display electrode pairs for selectively illuminating unit luminescent areas. Phosphors are arranged, in order to avoid damage by ion bombardment, on the other substrate facing the display electrode pairs with a discharge space between the phosphor and the display electrode pairs and are excited by ultra-violet rays generated from a surface discharge between the display electrodes, thereby causing luminescence. See for example, U.S. Pat. No. 4,638,218 issued on Jan. 20, 1987 and No. 4,737,687 issued on Apr. 12, 1988.
The full color display is obtained using an adequate combination of three different colors, such as red (R), green (G) and blue (B), and an image element is defined by at least-three luminescent areas corresponding to the above three colors.
Conventionally, an image element is composed of four subpixels arranged in two rows and two columns, including a first color luminescent area, for example, R, a second color ′luminescent area, for example, G, a third color luminescent area, for example, G, and a fourth color luminescent area, for example, B. Namely, this image element comprises four luminescent areas of a combination of three primary colors for additive mixture of colors and an additional green having a high relative luminous factor. By controlling the additional green area independent from the other three luminescent areas, an apparent image element number can be increased and thus an apparent higher resolution or finer image can be obtained.
In this arrangement of four subpixels, two pairs of display electrodes cross an image element, i.e., each pair of display electrodes crosses each row or column of subpixels, which is apparently disadvantageous in making image elements finer.
If the image elements are to be finer, formation of finer display electrodes becomes difficult and the drive voltage margin for avoiding interference of discharge between different electrode lines becomes narrow. Moreover, the display electrodes become narrower, which may cause damage to the electrodes. Further, a display of one image element requires time for scanning two lines, which may make a high speed display operation difficult because of the frequency limitation of a drive circuit.
The present invention is directed to solve the above problem and provide a flat panel full color surface discharge type plasma display device having fine image elements.
JP-A-01-304638, published on Dec. 8, 1989, discloses a plasma display panel in which a plurality of parallel barriers are ranged on a substrate and luminescent areas, in the form of strips defined by the parallel barriers, are formed. This disclosure is, however, In directed only to two electrode type plasma display panels, not to a three electrode type plasma display panel in which parallel display electrode pairs and address electrodes intersecting the display electrode pairs are arranged and three luminescent areas are arranged in the direction of the extending line at the display electrode pairs as in the present invention.
The present invention is also directed to a plasma display panel exhibiting a high image brightness at a wide view angle range. In this connection, U.S. Pat. No. 5,086,297 issued on Feb. 4, 1992, corresponding to JP-A-01-313837 published on Dec. 19, 1989, discloses a plasma display panel in which phosphors are coated on side walls of barriers. Nevertheless, in this plasma display panel, the phosphors are coated selectively on the side walls of barriers and do not cover the flat surface of the substrate on which electrodes are disposed.